As for hours - sorry but its not just trainees who may need to work long hours. Associates, senior associates, counsels, partners - you work anytime, anywhere in order to deliver what the client wants. You must work for a pretty well balance law firm if only the trainees need to stay until 9:30pm, and 9:30pm is considered really late lol.
Pay and working hours also vary greatly depending on the firm you join and the department you work in (US vs local vs UK firm, general litigation vs arbitration vs IPO for example). If having your life revolve around work isn't for you, accumulate enough experience and go in-house. Most who do do not regret their decision. There are options.